1. Field of the Invention
The present invention relates to a safety interlock system, and more particularly to a safety interlock system for a flow control apparatus. More specifically, the present invention relates to a safety interlock system using a magnet-less administration feeding set with an enteral feeding pump.
2. Prior Art
Enteral feeding systems are frequently used for patients who are unable to take nutrition alone and require some type of feeding system to provide nutrition through a gastrointestinal tract of a patient, such as the stomach. Typically, an enteral feeding system comprises a disposable administration feeding set in conjunction with a flow control apparatus, such as a pump, for supplying fluid to a patient at a controlled delivery rate. The administration feeding set of the prior art includes an inlet tube in communication with a source of fluid at one end and a drip chamber which is arranged to be mounted along a first recess on the pump at the other end, a mounting member for mounting the administration feeding set to a second recess on the pump, and a pump tube which connects the drip chamber to the mounting member while engaging a motor driven rotor on the pump.
In many enteral feeding systems the engagement of the pump tube to the rotor controls the flow of fluid to the patient according to the speed of the rotor. In the event the administration feeding set is not properly mounted to the pump, an excess flow of fluid through the feeding set can occur under force of gravity which is highly undesirable. Improper mounting of the drip chamber is unlikely because of the mechanical configuration of that component and its corresponding recesses on the pump. However, improper placement of the mounting member, e.g. below, above or outside of the respective recess on the pump is more likely if the administration feeding set is improperly installed on the pump by an inexperienced operator who has not yet received proper instruction in the operation of the enteral feeding system. Instances of such improper installation of the administration feeding set have been reported.
U.S. Pat. Nos. 4,913,703; 5,201,711; and 6,017,326 to Pasqualucci et al. disclose a safety interlock system for a flow control apparatus provided with a magnetic field source in the region of its mounting to an administration feeding set having a magnetic source, such as a magnet, incorporated into the mounting member. The flow control apparatus includes a magnetic field sensitive switching component which detects the proper placement of administration feeding set in the recess of the flow control apparatus and prevents operation of the flow control apparatus unless the mounting member of the administration feeding set is in a properly engaged position to the pump. Although the safety interlock system of Pasqualucci et al. provides an excellent means of ensuring proper engagement of the administration feeding set on the flow control apparatus, the magnet used to provide the magnetic source on the disposable administration feeding set makes it relatively expensive to manufacture.
Therefore, there appears a need in the art for a safety interlock system that is inexpensive to manufacture. There is a further need in the art for a safety interlock system that does not require an administration feeding set having a magnet in order to ensure proper placement of the feeding set on the flow control apparatus.